Pest Control

Rats

Rats can transmit diseases, contaminate food and utensils and damage buildings by chewing conduits and wiring.

The two most common types of rats that live in suburbs are:

Black rat

Brown rat.

Both of these rats were introduced from Asia and have a well known history of carrying pests and diseases. Brown rats tend to burrow and build nests around the foundations of buildings. Black rats tend to nest in roofs.

In Australia we also have two native rats know as the Bush Rats and Water Rats. Both are protected species and it is illegal to harm them. They are nocturnal and very timid and unlikely to live in urban areas.

Signs of rodent activity

The following may be signs of rodent activity:

Droppings (12mm to 18mm long)

Debris such as snail shells with the sides eaten out, almond shells, cape lilac berries, bones etc left in the corners of sheds, under homes and in secluded spots

Signs of fruit and vegetables having been eaten

Greasy rub marks along paths

Burrow holes around buildings

Signs of gnawing damage

Pet dogs, cats, birds, being more excitable than usual

Squeaking, gnawing or movement noises in walls, cupboards, ceilings and under floors.

Rat prevention and removal

The following are tips to prevent or get rid of rodents:

Store firewood away from the sides of sheds and fences and keep it well clear of the ground

Rubbish bins and compost containers should be well-maintained and free from holes

Don’t compost meat scraps

Trim trees away from gutters, patios and pergolas

Encourage neighbours to remove excess rubbish from their property.

Poison baits are the most successful way of destroying rats. The City's Environmental Health Branch supplies a limited quantity of rat poison for residential premises (but not commercial or industrial premises). These can be collected from the City's Civic Centre at 61 Broun Avenue Morley.

Mosquito

Mosquitoes

There are approximately 30 species of mosquitoes within Western Australia. Mosquitoes are considered to be major pests and carriers of viruses, including:

Ross River Virus (RRV)

Barmah Forrest Virus (BFV)

Murray Valley Encephalitis Virus (MVE).

Mosquito control program

The City's Environmental Health Branch undertakes a mosquito control program in collaboration with other local authorities and the Department of Health to implement the most effective control measures possible.

The program involves:

Monitoring and trapping of mosquitoes

Treatment of public areas identified as breeding sources

Investigating community complaints

Maintaining drainage systems to prevent water pooling.

Breeding pools of water are treated with larvicides, which either kill the mosquito larvae or prevent them from developing into adults. Follow up monitoring is undertaken to ensure the effectiveness of the treatments.

When there is an increased incidence of disease and when directed by the WA Department of Health, it may be necessary to fog using adulticides. This course of action is the least effective as it only kills adult mosquitoes and does not prevent breeding. It is also the least environmentally-friendly method of control.

Mosquito numbers can vary from year to year with about every second or third year being particularly bad. This can be caused by unusual climatic conditions such as the La Nina effect that can create unusually high tides, resulting in semi-permanent pools of water in low-lying river areas.

Under normal circumstances, these areas would dry out between tides and break the mosquito breeding cycle. These pools are capable of producing continuous breeding, covering several mosquito breeding stages simultaneously. In addition, the increased flushing by tidal action has been found to dilute the active ingredient of larvicides, thereby reducing their effectiveness and longevity.

Unusually high rainfall periods can also create higher than usual water levels and increased breeding.

In addition to the foreshore and wetland mosquito control program, the City's officers treat stormwater drains that hold water. These can cause problems when summer rainfall occurs or if sprinkler overspray runs into roadside stormwater gullies.

It should be noted that a mosquito control program will not completely get rid of mosquitoes, but aims to reduce breeding to acceptable levels.

Mosquito prevention

Mosquitoes can be controlled by householders in a number of ways:

Prevent breeding around your house

Make sure fish ponds and swimming pools are not breeding mosquitoes. Fish ponds should be stocked with mosquito larvae feeding fish e.g. goldfish. Swimming pools should be properly maintained and have clean, chlorinated water.

Protect your home

Place fly wire on all doors and windows

Make sure lids are sealed on septic tanks, soakwells and leach drains

Ensure your sewerage vent pipe has a mosquito-proof cowl, and if it is metal, make sure

the holes have not rusted through. Your vent pipe is usually located outside, adjacent to

your bathroom or laundry and running up the side of the house and through the roof

Put fly wire around rainwater tank inlets and overflows

Cut back foliage that provides homes for mosquitoes.

Personal protection

Avoid exposure at dusk and early evenings

Wear loose-fitting, long clothing outdoors

Use a suitable personal insect repellent.

White Cedar Moth Caterpillars

White Cedar Moth Caterpillars

Also known as Cape Lilac Tree Caterpillars, they can be a nuisance each year, usually around autumn. These caterpillars can invade homes by crawling over paths, walls and inside buildings.

The Cape Lilac Tree Moth is a prolific breeder and it is not unusual for a Cape Lilac Tree to have more than 2000 caterpillars feeding on the leaves.

The caterpillars go up the tree at dusk to feed and come down the trunk at sunrise to find a cool, dark place to hide.

How to deter White Cedar Moth caterpillars

The Department of Agriculture has advised that spraying trees for the caterpillar is ineffective, as they are fairly resistant to pesticide.

The best method of reducing numbers is to tie a piece of hessian (sacking) around the base of the tree affected. The caterpillars will congregate under the hessian to shelter from the light and heat of the day allowing easy removal and disposal. They can then be placed into an enclosed container and killed using a liberal dose of insecticide or physical means.

The tree bagging process may have to be repeated a number of times to reduce numbers to acceptable levels. Hot, dry weather usually kills them off naturally, as does the colder winter weather.

To stop caterpillars entering the house you can use rolled-up hessian, surface sprays or washing powder at doorways and openings.

For further information, contact the Department of Agriculture on 9368 3333.

Bees

Bees

Bees typically swarm in the spring of each year, prior to establishing new hives. Swarming is part of the natural reproductive life cycle of honey bee colonies. The swarm will often remain for a day or two while scout bees search for a new home or it may move to another location. Should a swarm decide to settle in your property:

Keep children and pets inside for half an hour or so, until the flying bees have clustered on to a bush or other object

Once the swarm has formed a cluster, usually about the size of a football, and most of the bees have stopped flying, it is safe to go outside and carry on as normal

Keep clear of the swarm until you can arrange to have it removed

Always wear footwear to protect your feet

Do not put the hose onto the swarm, throw stones at it, smoke the bees out or take similar action. These “do-it-yourself” remedies will aggravate bees, encouraging them to sting in defence.

Bees on public land

If you notice a bee swarm or hive on public land, such as a park or street verge and you think it may be a public danger, contact the City's Environmental Health Branch on 9272 0648.

The City will arrange for an officer to assess the situation and if it is considered a danger, a professional bee removalist or pest control operator will be sent to relocate or eradicate the swarm.

Bees on private property

If a bee swarm or hive is on private property, it is the owner’s responsibility to arrange for it to be removed.

European Wasp

European Wasps

The European wasp is an introduced species that was first detected in Australia in 1959. Since then, it has spread to many parts of the country including Perth. The wasp enjoys the warmer Australian conditions and nests can grow to 3m in length and contain hundreds of thousands of wasps. Because they are attracted to cool drink and meat, they are a particular hazard around barbecues and also for pets. If swallowed, they can sting repeatedly (unlike a bee that can only sting once) and cause asphyxiation through swelling.

European wasps have been known to:

Attack bees and bee hives, robbing the hives of honey and sometimes completely destroying them

Damage soft fruits

Cause environmental damage through direct predation on native insects

Compete with other species including birds.

They are also extremely aggressive, sting repeatedly with little or no provocation and if they do get established will seriously impact on our outdoor way of life by spoiling BBQs and alfresco dining.

Normal Paper Wasp

Physical features

The European wasp is about the same size and shape as a honey bee, but is not hairy.

European wasps have:

Long, black antennae,

The wings are folded when resting

Legs are held close to their body when they fly

Distinct bright yellow and black triangle-shaped markings on the body.

It is not to be confused with the Papernest wasp that is more slender and has an obvious waste section. Please see the above photo of European wasp. The normal paper wasp is pictured to the right.

Wasp nests

The European wasp’s nest is always concealed. It is usually underground but can be located inside a hollow tree, a space in a retaining wall or embankment, in a wall cavity or the ceiling space of a house. The nest varies in shape depending on its location but can be very large. It consists of layers of cells and the outside is covered with flaky pieces of chewed up and cemented wood fibre.

The Papernest wasp’s nest, in contrast, is usually small (about the diameter of a 50-cent coin), fully or partially exposed, honeycombed in appearance and is often found on the underside of eaves or hanging off a branch.

Take precautions against European wasps by:

Keeping food, drink or pet food inside

Picking up fallen fruit

Ensuring that your outdoor rubbish bins have tight-fitting lids

Covering compost bins

Covering food during a barbecue or picnic

Drinking from a straw (don’t drink straight from a can or bottle when outside).

What to do if you see European Wasps?

If you see a European Wasp leave it alone – it will only attack if provoked.

All suspected European Wasp sightings must be reported to the Agriculture Protection Board of WA on 9368 3472.

Please do not attempt to remove the nest yourself as this can be extremely dangerous.